The present invention relates to cassettes which contain a magnetically affixable printing tape and tape printers which print data on the printing tape.
Conventionally, tape printers are widely used which print a character string on a printing tape and which cut a printed portion from the printing tape to produce a label.
Tape cassettes used in the printers contain a pair of reels around which a printing tape and an ink ribbon are wound, respectively. The printing tape includes a printing layer of a resin film with an adhesive layer coated on its side and a separable paper strip adhered to the printing layer through the adhesive layer. The tape cassette is set on the tape printer and feeds the printing tape and the ink ribbon to a printing section.
The label produced by the tape printer can be pasted on a desired object by separating its separable paper piece therefrom. Once pasted on the object, the label cannot be easily separated from the object because it strongly adheres to the object.
A magnet sheet is known, from which a smaller sheet piece of a desire it size is obtained. Appropriate characters are handwritten on the smaller sheet piece, which is then affixed magnetically, for example, to a white board of steel or another magnetic object for use.
However, the conventional magnet sheet is not composed in consideration of printing in the tape printer and is not suitable for printing. Thus, tape-like magnet materials are desired from which labels are obtained on the tape printer. The inventors have made a series of studies to put to a practical use magnetically affixable printing tapes on which characters/images are printable by the tape printer.
First, in order that the magnetically affixable printing tape may be used in the tape printer like the conventional printing tape with, an adhesive on its side, a magnetically affixable printing tape consisting of a printing layer and a magnetic layer pasted to the printing layer is required to be wound around a reel, and a resulting roll of the printing tape is required to be accommodated within a cassette. Since the printing tape is wound repeatedly around the reel in a superimposing manner, there may occur a trouble, for example, with conveyance of the tape depending on a magnetic pole arrangement pattern formed on the tape, as we have found. For example, a magnet sheet has magnetized lines along which the S and N poles of a particular width alternately arranged extend. A magnetically affixable tape is required to be produced appropriately from the magnet sheet by paying careful attention to the, magnetized lines. Otherwise trouble would occur when a roll of such tape is accommodated within the tape cassette and characters/images are then printed on a tape portion fed out from the cassette.
More specifically, when a magnetic tape is magnetized lengthwise or in a direction of its conveyance, S and N poles are alternately formed so as to be arranged widthwise in the tape and to extend lengthwise of the tape. When such magnetized printing tape is wound repeatedly around a reel in superimposing manner, magnetic poles of the same polarity of adjacent turns of the tape can be superimposed. Thus, a repelling force would occur between those poles and hence their adjacent turns of the tape. Thus, one of those adjacent turns would shift widthwise of the tape relative to the other of the tape turns. Since such repelling force is applied perpendicular to the direction of tape conveyance, the tape is likely to meander when it is conveyed to the printing section to thereby hinder appropriate printing.
When the printing tape is wound around a holding reel, a magnetic layer of one turn of the tape is brought into contact with a back of a printing layer of the adjacent turn. In this case, small particles or grains of the magnetic layer, which contains a mixture of a synthetic resin or synthetic rubber and magnetic powder, would shift to a surface of the printing tape to soil the same, as we found. A printer of this type generally employs a heat-transfer printing system. When inks of the conventional ink ribbon are not supposed as being toed to pint characters on the printing tape, characters/images printed on the tape would be blurred, which is a new problem.
The ink ribbon consists generally of a base film of capacitor paper, glassine or a resin film of polyester or a polyimide resin, and an ink layer coated on the base film. The ink layer includes a mixture of a wax or resin and a coloring agent such as a pigment. When an ink of the ink layer is transferred to the printing medium, a luster occurs on a surface of the ink-transferred to the printing medium, especially in the heat transfer system. In order to suppress this luster, a luster suppressing additive is added into the ink layer or a luster control layer is provided between the base film and the ink layer.
In many cases, a pigment added as a coloring agent to the ink layer is, for example, carbon black or an iron oxide in the case of a black ink. Similarly, the luster control layer contains an iron oxide pigment for delustering.
We also have found in a test for putting the tape to practical use that the xe2x80x9cblursxe2x80x9d of the characters printed on the printing tape are due to exertion of the magnetic drawing force of the magnetic layer on the iron oxide pigment contained in the ink layer/luster control layer.
When once a label produced from the magnetic tape is affixed magnetically to a magnetic object, it is difficult to separate the former from, the latter.
When the magnetically affixable printing tape contained in the tape cassette is used substantially up to As end, a small end portion of the tape is likely to remain in, be drawn against, the printer and enter a space in the printer and is difficult to remove.
In color printing by the tape printer the printing tape is reciprocated so as to assume the same printing start position to thereby perform superimposing print in yellow, magenta and cyan inks. In the conventional tape printer, control of quantities of reciprocation of the tape is provided by sensing with an optical sensor a plurality of marks printed at equal intervals lengthwise on the back of the tape and then counting the sensed number of marks.
However, the surface of the magnetic layer generally has a dark color such as brown. In this case, if a plurality of position marks are printed in white at equal intervals such that they can be easily sensed by the optical sensor, they are required to be more or less thick. Thus, irregularities would be produced on the surface of the magnetic layer due to the presence of the marks printed on the surface of the magnetic layer which is brought into contact with the object. Those irregularities would produce gaps between the magnetic layer and the object to thereby reduce the magnetic drawing force of the magnetic layer.
It is therefore a first object of the present invention to provide a cassette which contains a magnetically affixable printing tape on which a magnetic pole arrangement pattern is formed to enable the tape printer to approximately print characters/images on the tape without causing trouble, for example, with the tape conveyance.
Another object of the present invention is to provide a cassette which contains a magnetically affixable tape in which no parts of the magnetic layer shift to a surface of the printing layer even when the printing layer is wound repeatedly along with the tape around a reel.
Still another object of the present invention is to provide a cassette which contains in combination an ink ribbon and a magnetically affixable printing tape by which no blurs occur when characters/images are printed on the tape in a heat transfer system.
A further object of the present invention is to provide a cassette which contains a magnetically affixable printing tape including a magnetic layer which provides a label which, even if it is once magnetically affixed to the object, can be easily separated from its object.
A still further object of the present invention is to provide a cassette which contains a magnetically affixable printing tape which even when it is used substantially up to its end, no small end portion, of the tape remains within the tape printer and hence no troubles occur.
A still further object of the present invention is to provide a tape printer which even when no marks for controlling a quantity of conveyance of a magnetically affixable printing tape are provided on the tape, is capable of controlling the quantity of conveyance of the tape for reciprocating purposes in color printing.
In order to achieve the; above objects, the present invention provides a cassette comprising a holding reel around which a magnetically affixable printing tape is wound, the cassette being settable in a tape printer which includes conveying means for conveying the tape of the cassette and printing means for printing characters/images on the tape,
the tape comprising a printing layer on which characters/images are printed by the tape printer and a magnetic layer containing magnetic powder magnetized widthwise of the tape and pasted at a side to the printing layer.
In a lengthwise magnetized magnetic layer, N and S poles which extend lengthwise the magnetic layer. Thus, when the magnetic tape is wound repeatedly around the reel, a magnetic pole of a polarity of one turn of the tape layer can be superimposed on another pole of the same type of an adjacent turn of the tape layer such that a repelling force occurs between those adjacent poles and those tape turns move widthwise relative to each other. According to the inventive tape, no such repelling force occurs and the tape is appropriately conveyed to the printing section to thereby provide appropriate printing.
In the cassette, a side of the magnetic layer pasted to the printing layer preferably has a coated fluororesin layer for preventing small particles or grains of the magnetic layer from moving to the printing layer when the magnetic layer comes into contact with the printing layer due to the magnetic layer and the printing layer being wound around the holding reel.
The side of the magnetic layer pasted to the pining layer may comprise a wrinkled one.
The ink of the printing ink ribbon accommodated along with the magnetically affixable in the cassette preferably contains a non-magnetic substance ink. By heat-transfer printing characters or images on the tape, using the ink ribbon, no ink transferred to the tape is magnetically drawn, and hence no printed characters/figures are blurred.
The magnetic layer has a non-magnetic area formed along at least one edge of the tape. Since a label produced from such magnetically affixable printing tape has the non-magnetized area a, it can be separated at one of those areas even when it is affixed magnetically to a ferromagnet such as steel.
The cassette preferably comprises an auxiliary non-magnetic tape provided at a trailing end of the magnetically affixable printing tape and bonded to the holding reel to such a degree that the auxiliary tape is separated, or is not separated, from the holding reel of the tape printer by a conveying force exerted by e convey means as the case maybe. By doing so, even when the tape is substantially used up, leaving its small end portion, which remains within the tape printer, it can be easily taken out because the auxiliary tape is attached to the printing tape end.
The present invention also provides a tape printer comprising:
a magnetically affixable printing tape comprising a printing layer on which characters/images are to be printed, and a magnetic layer of magnetic powder pasted to the printing layer and magnetized such that N and S poles are alternately arranged longitudinally of the magnetic layer;
conveying means for reciprocating the tape a plurality of times along a conveyance path in one and the other directions;
printing means for printing characters/images on the tape in a plurality of color inks sequentially in superimposing relationship when the tape is conveyed in the one direction by said conveying means;
detecting means for detecting changes of magnetic poles of the tape which passes a predetermined position along the conveyance path when the tape is reciprocated in the conveyance path by said conveying means; and
conveyance control means for counting the number of changes of magnetic poles of the tape detected by the detecting means to control a quantity of conveyance of the tape by said conveying means such that a quantity of conveyance of the printing tape in the one direction becomes equal to a quantity of conveyance of the tape in the other direction.
According to this tape printer, the changes of magnetic poles of the magnetically affixable tape which passes the predetermined position along the conveyance path is detected by the detecting means in the tape conveyance and the quantity of reciprocation of the tape is controlled based on the number of detected changes of the magnetic poles. Thus, even if there are no conveyance quantity control marks formed on the tape, the quantity of reciprocation of the tape is controlled appropriately.